MRF49XA Datasheet, PDF (12/102 Pages) Microchip Technology – ISM Band Sub-GHz RF Transceiver

MRF49XA
TABLE 2-1: PIN DESCRIPTION (CONTINUED)
Pin
Symbol
Type
Description
9
RFXTL/EXTREF
Analog Input RF Crystal: This pin is connected to a 10 MHz series crystal
or to an external oscillator reference. The crystal is used as a
reference for the PLL which generates the local oscillator
frequency. It is possible to “pull” the crystal to the accurate
frequency by changing the load capacitor value.
External Reference Input: An external reference input, such
as an oscillator, can be connected as a reference source.
Connect the oscillator through a 0.01 μF capacitor.
10
RESET
Digital Input/Output Active-low hardware pin. This pin has an open-drain Reset
output with internal pull-up and input buffer. Refer to
Section 3.1 “Reset” for more details.
11
Vss
Ground
Ground reference.
12
RFP
RF Input/Output Differential RF input/output (+).
13
RFN
RF Input/Output Differential RF input/output (-).
14
VDD
Power
RF power supply. Bypass with a capacitor close to the pin.
See Section 2.1 “Power and Ground Pins” for more
details.
15
RSSIO
Analog Input/Output Received Signal Strength Indicator Output: The analog
RSSI output is used to determine the signal strength. The
response and settling time depends on the external filter
capacitor. Typically, a 4-10 nF capacitor provides optimum
response time for most applications.
16
INT/DIO
Digital Input/Output Interrupt: This pin can be configured as an active-low
external interrupt to the device. If a logic ‘0’ is applied to this
pin, it causes the IRO pin to toggle, signaling an interrupt to
the external microcontroller. The source of interrupt can be
determined by reading the first four bits of STSREG (see
Table 2-4). This pin can be used to wake-up the device from
Sleep.
Data Indicator Output: This pin can be configured to
indicate valid data based on the actual internal settings.
DS70590B-page 10
Preliminary
© 2009 Microchip Technology Inc.